The scapholunate ligament is one of the intrinsic ligaments of the carpus: that is, it is not a ligament of the joint capsule external to the joint, but is located within the wrist joint, between the scaphoid and lunate bones. Anatomically, the scapho-semilunar ligament is differentiated into three parts: volar, membranous and dorsal.
The function of this wrist ligament is very important as it prevents the scaphoid and lunate bones from separating when making a firm fist (e.g. to squeeze a small object) or when rotating the forearm while supporting a weight with the hand (e.g. when lifting a weight from the floor to place it on top of a high table).
Scaphosemilunar wrist ligament injury
This ligament of the carpus can be damaged with a fall to the ground on the palm of the forced hand or when suffering a sudden turn of the hand, as for example, when drilling a wall the drill bit is blocked, it is a frequent pathology in the consultation of Traumatology.
When this ligament is damaged, the symptoms are pain in the center of the wrist when extending it, for example when supporting the hands to get up or when making flexions. The patient will also present loss of strength to lift weights with the elbow extended, and may even notice protrusions of the wrist bones when turning the wrist.
The ligament may be injured to varying degrees depending on which surface and portion of the ligament is torn. Logically, the larger the damaged ligamentous surface, the lesser its function in maintaining the scaphosphemilunar space, the greater the loss of wrist function, the greater the patient’s discomfort and the greater the indication for surgical treatment.
Non-surgical treatment of scapholosemilunar ligament injury
Recent anatomo-pathological studies have shown that the scapho-semilunate ligament has microscopic corpuscles called mechanoreceptors that are capable of controlling wrist proprioception: that is, the body has internal control systems to prevent scaphoid and lunate from separating during weight bearing or wrist movement. This explains why patients with scapholosemilunate ligament injury have very little discomfort.
Similarly, specialists in neuromuscular control of the wrist have shown that there are muscles in the forearm that can compensate for scapholosemilunar ligament rupture if properly worked.
Currently many of these ligament injuries are treated with specific proprioceptive rehabilitation with very good results.
Surgical treatment of scapholosemilunar ligament injury
The scaphosemilunar ligament should be operated on in these two cases:
- When the static or dynamic mechanics of the wrist are altered.
- When proprioceptive rehabilitation does not work
Currently this wrist operation can be performed by arthroscopy, by open surgery or by combining both techniques.
The methodology chosen will depend on the degree of ligament injury, how the carpal bones behave mechanically and the preferences of the orthopedic surgeon.
However, wrist arthroscopy offers advantages over open surgery when it is well indicated and technically perfected. The patient operated by arthroscopic surgery obtains better mobility of the wrist than the one operated by open surgery, because the scars of the joint are much smaller.
Recovery from wrist surgery
Regardless of the surgical technique used for scapholunate ligament injury, the patient should be aware that mobility and strength will not be restored until three months after surgery and that the surgeon will not allow contact sports or risky activities until six months after surgery.